Add instruction priority hierarchy to using-superpowers skill

Clarifies that user instructions (CLAUDE.md, direct requests) always
take precedence over Superpowers skills, which in turn override
default system prompt behavior. Ensures users remain in control.

Also updates RELEASE-NOTES.md with unreleased changes including
the visual companion feature.

skills/using-superpowers/SKILL.md

@@ -11,6 +11,16 @@ IF A SKILL APPLIES TO YOUR TASK, YOU DO NOT HAVE A CHOICE. YOU MUST USE IT.
 This is not negotiable. This is not optional. You cannot rationalize your way out of this.
 </EXTREMELY-IMPORTANT>
 
+## Instruction Priority
+
+Superpowers skills override default system prompt behavior, but **user instructions always take precedence**:
+
+1. **User's explicit instructions** (CLAUDE.md, direct requests) — highest priority
+2. **Superpowers skills** — override default system behavior where they conflict
+3. **Default system prompt** — lowest priority
+
+If CLAUDE.md says "don't use TDD" and a skill says "always use TDD," follow CLAUDE.md. The user is in control.
+
 ## How to Access Skills
 
 **In Claude Code:** Use the `Skill` tool. When you invoke a skill, its content is loaded and presented to you—follow it directly. Never use the Read tool on skill files.